This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Bioactive lipids, such as prostaglandin E2 (PGE2), are signaling molecules generated by cells of the immune system to regulate inflammation in humans. Bioactive lipids are also biosynthesized by fungi, such as the pathogen Candida albicans and the saprophyte Saccharomyces cerevisiae (brewers yeast). The latter is employed to manufacture a wide range of foods, pharmaceuticals and vaccines. We aim to identify the categories of products consumed by humans that contain bioactive lipids produced by S. cerevisiae and define the biosynthetic pathway(s) used by the fungus to produce bioactive lipids. Understanding how fungi generate bioactive lipids will inform of strategies for limiting bioactive lipid biosynthesis during product manufacture. The proposed research is initially focused upon PGE2 because it is one of the better-understood bioactive lipids and is produced by S. cerevisiae. The outcome measure of this study will be determining whether bioactive lipids are absent or present in select products manufactured using S. cerevisiae. The UCSF Mass Spectrometry Facility can assist in obtaining our research goals by analyzing extracted lipids from select products for the presence of bioactive lipids such as PGE2, using liquid chromatography-mass spectrometry (LC-MS).